1. Field of the Invention
The present invention relates to a syringe, and more particularly to a safety syringe that can safely retract a used needle back into a barrel and prevent users from being hurt by the used needle.
2. Description of Related Art
There are two types of conventional syringes used for taking blood, one has a hollow barrel, a plunger and a needle hub, and the other has a short holder, an inner needle and a needle hub. The plunger of the first type is received inside the hollow barrel, and the needle hub is connected to the hollow barrel. The short holder of the second type has an outside surface, a bottom surface and an inner space. The needle hub is mounted on the bottom surface of the outside surface and the inner needle mounted on inner space and connects to the needle hub.
When using the first type of the conventional syringe, a user takes blood into the hollow barrel then inserts the collected blood into a vacuum tube. When using the second type of the conventional syringe, the needle hub is inserted into a vein and a vacutainer is connected to the inner needle inside the short holder. Because of the attraction of the vacutainer and the blood pressure, blood will flow into the vacutainer slowly.
However, the used needles extended outside the hollow barrel or the short holder of the conventional syringes will easily hurt users after taking blood. To keep nurses, doctors or health workers who deal with discarded syringes from being injured or infected by used needles, a safety syringe for taking blood is needed. In another aspect, the short holder of the second conventional syringe is too easily reused to hold a new needle and unscrupulous staff may be tempted to reduce costs in this way whereby serious unsanitary conditions will be met.
To overcome the shortcomings of conventional syringes, the present invention provides a safety syringe to mitigate or obviate the aforementioned problem.